Presentation on what radical reactions are, how they occur, and what they can be used to produce. We also discuss the use, manufacture, and environmental/health and safety concerns of PVC, or polyvinyl chloride.

1. RADICAL
REACTIONS AND
PVC
Presenters: John, Misha, and Kira
Instructor: Jiyoung Jung

2. WHAT ARE RADICAL
REACTIONS?
A brief introduction

3. What are radicals?
■ Radicals
– Reactive intermediates
– Single unpaired electron
– Formed by homolytic cleavage
■ Occurs infrequently due to high activation energy
■ Requires high heat, light or a radical initiator (RO-OR)
■ Radical reactions are chemical reactions involving the use of radicals

4. RADICAL REACTION
MECHANISMS
Common reactions involving radicals

5. Radical electron movement
■ Homolytic cleavage
■ Pi bond addition
■ Hydrogen abstraction
■ Halogen abstraction
■ Elimination
■ Coupling (Klein)

6. Radical halogenation mechanics
Proceeds in a “chain reaction” fashion
Conditions: X2 and hv or Δ
1. Initiation:Two radicals form by homolysis of a σ bond
2. Propagation: A radical reacts with another reactant to form a new σ
bond and another radical
3. Termination:Two radicals combine to form a stable σ bond
(Klein)

7. APPLICATIONS OF
RADICAL REACTIONS
Industrial uses

8. Polymerization
■ Radical reactions can be used to link
together monomers, or small
chemical units, into a chain called a
polymer
– Biological importance: Proteins,
carbohydrates, nucleic acids
– Industrial importance: Synthetic
plastics (polyethylene,
polyvinylchloride, polystyrene)
(Klein)

10. Uses of Polymers

11. PVC – POLYVINYL
CHLORIDE
Background information, importance, and applications

12. PVC [Polyvinyl chloride]
■ IUPAC name: poly(1-chloroethylene)
■ Chemical formula: (C2H3Cl)n
■ Soluble in tetrahydrofuran.
■ Insoluble in alcohols.
Chemical Structure
Tetrahydrofuran

13. Appearance
Raw form of PVC
After Plasticizer
Two types rigid and
flexible

14. PVC Monomer and Polymer
Polymerization

15. Synthesis of PVC
• In the initiation step, the
radical for the reaction is
formed.
• The propagation step
shows how the radical is
used to form other
radicals, chaining them
together into a polymer.
• The termination step
finalizes the polymer by
removing the unpaired
electron from it.

16. Physical and Chemical Properties
■ They depend on how the PVC is produced. Properties differ depending
on what is made.
■ Unplasticized PVC is rigid. Plasticized PVC is a flexible, sturdy plastic.
– Melting point: 100-260°C (Wilkes, Charles E, et al.)

17. Applications of PVC
■ “Today, PVC serves more than 70% of the construction market for
plastics, dominating pipe and fittings, sidings, windows, fencing, and
decking (Rahman).”

18. Applications of PVC
■ “54,000 DrinkingWater Systems Serving …
– 264 Million+ People in the U.S.,Via …
– 2 Million Miles ofWater Distribution andTransmission Pipe
■ 60,000+ Sanitary Sewer Systems Serving …
– 264 Million+ People in the U.S.,Via …
– 2.5 Million Miles of Sewer Mains and Service Lines”
(Rahman)

19. Environmental Impacts
■ "Many PVC products end up as plastic marine debris" that can be harmful to marine
life and the habitats they live in.
■ PVC contributes to the micro-plastic issue that the world is facing, especially because
it makes up most of the plastic we use today for transport, packaging, electronics, and
healthcare applications. The demand is expected to rise 3.2% per year until at least
2020.
■ This means pollution will increase as well. So there are studies being done to try
to figure out different methods of degradation.

20. https://www.youtube.com/watch?v=uwHRAoxhUcI

21. Health Impact
“PVC contains chemicals that may have adverse health effects:
■ Exposure to PVC often includes exposure to phthalates and chlorine.
■ Manufacturing, burning, or landfilling PVC releases dioxins.
■ Phthalates, dioxins, and BPA are suspected to be endocrine disruptors.
■ Consumers
– Plastic products for construction, medical, and home use contain PVC.
■ Children
– Many plastic and vinyl products for children contain PVC.”
(US National Library of Medicine)

22. Conclusion
■ Radicals are highly reactive atoms with a single unpaired electron.
■ Radicals often form through homolytic cleavage.
■ Radical halogenation occurs in a three-step mechanism.
■ Polymerization chains together monomer units.
■ Polyvinyl chloride is a useful polymer made of vinyl chloride monomers and is mainly
used for making pipes and other industrial applications.
■ Application of PVC
■ Environmental and health impacts.

23. Citations
■ AUS-e-TUTE. PolyvinylChloride (PVC) . n.d. 22 January 2019.
■ Endo, Kiyoshi. "Synthesis and structure of poly(vinyl chloride)." Progress in Polymer
Science (2002): 2021-2054.
■ Hardinger, Steven A. Illustrated Glossary of OrganicChemistry - Polyvinyl chloride
(PVC). 2017. 22 January 2019.
■ Klein, David R. OrganicChemistry.Wiley, 2013.
■ Lenntech. PolyvinylChloride (PVC). n.d. 22 January 2019.

24. Citations
■ Rahman, Shah. PVC Pipe & Fittings: Underground Solutions forWater and
Sewer Systems in North America. FortWorth,Texas, 19 June 2007. PDF
Presentation.
■ Tang,Chih-Cheng, et al. "Textural, Surface and Chemical Properties of Polyvinyl Chloride
Particles Degraded in a Simulated Environment." Marine Pollution Bulletin, vol. 133,
2018, pp. 392-401.
■ The Editors of Encyclopedia Britannica. Polyvinyl chloride. 17 January 2019. 22
January 2019.
■ US National Library of Medicine.ToxTown - PolyvinylChloride (PVC). 31 May 2017. 22
January 2019.
■ Wilkes, Charles E, et al. PVC Handbook. Hanser, 2005.